DEVICE AND METHOD FOR OPTICALLY CAPTURING A DOCUMENT

Description

Technical area

[0001] The present invention relates to a device and a method for optically capturing a document. Description of the state of the art

[0002] Document readers for capturing data pages from identification documents, particularly passports, are known from the state of the art. Such readers are used, for example, at airports in connection with automated passport verification (electronic border control).

[0003] On the one hand, systems are known in which the passport to be checked is moved on a carriage (tray) past an optical capture device such as one or more scanner lines or a camera (see, for example, DE 10 2012 211 076 A1 and DE 10 2012 215 845 A1). Furthermore, systems are also known in which the document to be checked is placed on a non-movable document support and illuminated from the opposite side. Light reflected from the placed document is then captured by a suitable capture device, such as a camera (see, for example, DE 10 2017 124 572 A1). EP 2 323 368 A1 discloses a reading device of the latter type in which a mirror is arranged below the document support, which redirects light reflected from the placed document into a camera provided for capturing the document.

[0004] US 2002 / 0191994 A1 discloses a scanning device for scanning two consecutive pages of an open book. The scanning support surface comprises two scanning sections made of glass panes arranged at an angle to one another, as well as a scanning carriage arranged below the support surface. The scanning carriage extends perpendicular to the junction between the two scanning sections, essentially across the entire width of the scanning support surface, and is movable back and forth parallel to the support surface. Each scanning section on the scanning carriage is assigned a scanning device comprising a lens and image sensor. An arrangement of reflection mirrors reflects the book pages placed on the scanning sections onto the image sensors, thereby enabling the simultaneous scanning of two pages of a book. Summary of the invention

[0005] Based on this, according to the invention, a device for optically capturing a document with the features of claim 1 and a method for optically capturing a document with the features of claim 4 suggested.

[0006] The invention is based on the idea of ​​designing a document support of a device for optically capturing a document with a first capturing section and a second capturing section. The first capturing section is associated with a first document section of a placed document, and the second capturing section is associated with a second document section of the placed document.

[0007] The invention thus opens up the possibility of completely scanning a document with two document sections, in particular an unfolded two-page passport, in a single scanning step. This eliminates a major source of error in electronic border control systems that scan only one passport page: the insertion of the "wrong" passport page. Unlike systems that scan both pages consecutively (successively placing the two document sections or scanning them using a mobile scanner or a carriage moving over a camera), the proposed invention does not require, or at least does not require significantly more time, than known single-page readers.

[0008] According to the invention, an optical detection arrangement with two detection devices (such as cameras) is provided. The first detection device is assigned to the first detection section, and the second detection device is assigned to the second detection section.

[0009] In order to keep the beam path sufficiently short (and the design of the device according to the invention as compact as desired), the beam path can be folded. A first deflecting mirror can be provided for deflecting the light coming from the first detection section to the first detection device, and a second deflecting mirror can be provided for deflecting the light coming from the second detection section to the second detection device. One or both deflecting mirrors can be designed to be partially transparent to further save space, allowing the two beam paths to be nested.

[0010] Furthermore, one or both capture sections can be designed to be switchably transparent. This can involve a known procedure in which glass is coated with a liquid crystal layer to which an electric current can be applied. This liquid crystal layer is transparent or opaque depending on the switching state. Alternatively, other switching options are conceivable, such as a mechanical blind solution. Switching the transparency of the capture section(s) opens up the possibility of switching the otherwise opaque capture section assigned to it to transparent in order to capture a document section, while the corresponding other capture section remains opaque. This avoids any incoming and disruptive extraneous light. In order to capture both document sections, the two capture sections are switched transparent / opaque one after the other, which is particularly advantageous.When using LCD solutions, this can be done in fractions of a second, so that scanning two passport pages takes only slightly longer than scanning just one page.

[0011] The present description also covers a computer program with program code suitable for executing a method according to the invention when the computer program runs on a processor or a suitable computer device / control device. Both the computer program itself and stored on a computer-readable medium (computer program product) are claimed.

[0012] Further advantages and embodiments of the invention emerge from the subclaims, the description and the accompanying drawings.

[0013] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention as defined in the claims.

[0014] The invention is illustrated very schematically in the drawings using an embodiment and is described in detail below with reference to the drawings. Brief description of the drawings

[0015] Figure 1 shows a device according to the invention for optically capturing a document in a side view. Figure 2 shows the device for optically capturing a document with a document placed on it in operation. Figure 3 shows a highly schematic block diagram of a device according to the invention with control device. Figure 4shows a block diagram to illustrate a method sequence according to the invention. Detailed description

[0016] Figure 1 shows a side view of a device 10 according to the invention for optically capturing a document. The device 10 comprises a document support 12 with a surface 14 designed for placing a document D (see FIG. Figure 2 ). The document D to be placed and scanned is, for example, a passport which, when unfolded (i.e., opened), is twice the size of a so-called ID-3 document (125 mm × 88 mm according to ISO / IEC 7810). This means that the surface 14 of the document support 12 has twice the ID-3 size (125 mm × 176 mm) (and is thus designed as a full-page passport reader).

[0017] The device 10 further comprises an optical detection arrangement 16 for detecting light reflected from the placed document. For illuminating the document D placed on the document support 12, a Figures 1 and 2 A lighting arrangement (not shown) is provided. Suitable lighting is known, for example, from DE 10 2014 205 363 A1.

[0018] According to the invention, the document support 12 comprises a first capture section 14.1 and a second capture section 14.2, which are designed such that the first capture section 14.1 is assigned to a first document section D1 of a document D placed on the surface 14, and the second capture section 14.2 is assigned to a second document section D2 of the placed document D. If the document D to be captured is a passport, the first document section D1 would correspond to a first page of the unfolded passport, and the second document section D2 would correspond to the opposite page of the unfolded passport. Each capture section 14.1, 14.2 then has ID-3 size.

[0019] According to the invention, the optical detection arrangement 16 comprises two detection devices 18.1, 18.2, wherein a first detection device 18.1 is assigned to the first detection section 14.1 and a second detection device 18.2 is assigned to the second detection section 14.2. The detection devices can be suitable image capture devices, such as suitable (digital) cameras, optical sensors (CMOS, CCD), or the like. In the figures, the detection devices are depicted highly schematically as cameras.

[0020] To achieve a compact design, the beam path of the light reflected from the document support can be folded. For this purpose, deflecting mirrors 20 are provided, as shown: a first deflecting mirror 20.1, which deflects light reflected from the first detection section 14.1 into the first detection device 18.1, and a second deflecting mirror 20.2, which deflects light reflected from the second detection section 14.2 into the second detection device 18.2.

[0021] To achieve a particularly compact design, the two deflection mirrors 20.1, 20.2 can be arranged in the beam path of the other deflection mirror, as can be seen from the illustration in the figures. Figure 2how light reflected by the second detection section 14.2 falls onto the second deflecting mirror 20.2 and is deflected by it toward the second detection device 18.2, with the first deflecting mirror 20.1 located in the deflected beam path. For this purpose, the two deflecting mirrors can be designed as partially transparent beam splitters, for which, in return, the amount of light for illuminating the placed document must be increased accordingly to compensate for the light loss at the beam splitter located in the beam path.

[0022] Furthermore, according to the invention, the first and / or second detection sections 14.1, 14.2 can be designed to be switchably transparent. As described above, this switchability can be electrically / electrochemically or mechanically. The document support is then switched to transparent at the moment the object lying on it is detected in the relevant detection section. This measure helps to prevent any incoming and disturbing extraneous light.

[0023] Figure 1 shows, by means of the hatching, both detection sections 14.1, 14.2 in an opaque state. Figure 2 shows the device 10 according to the invention with the opened passport D placed on it, with a first passport page D1 resting on the first detection section 14.1 and a second passport page D2 resting on the second detection section 14.2. The snapshot of the Figure 2shows how the second detection section 14.2 is switched transparently (illustration without hatching) and indicates the beam path of the light reflected from the applied second passport side D2 to the second deflection mirror 20.2 and from there through the partially transparent first deflection mirror 20.1 to the second camera 18.2.

[0024] During operation, a document D having a first document section D1 and a second document section D2 is thus placed on the surface 14 of the document support 12 of the device 10 according to the invention, without any alignment or orientation of the two document sections having to be taken into account.

[0025] After the document D has been placed on the scanner, the two document sections D1, D2 are illuminated from the opposite side of the document support 12 in a manner known per se, whereby initially no light falls on the two document sections D1, D2, since the associated detection sections 14.1, 14.2 are switched to be non-transparent (cf. Figure 1 ).

[0026] To capture document D, the capture devices assigned to the two capture sections 14.1 and 14.2 are then triggered one after the other. Before each triggering, the corresponding capture section 14.1 or 14.2 is switched to transparent and then switched back to opaque.

[0027] The control can be carried out by means of a control device C, which, for example, as in Figure 3 can be connected schematically.

[0028] Accordingly, the control device C is connected to the detection sections 14.1 and 14.2 as well as the correspondingly assigned detection devices 18.1 and 18.2. Likewise, the control device C is connected to a lighting arrangement B, which, for example (as in Figure 3 indicated) can be configured as a frame surrounding the document support 12. Alternative types of illumination are familiar to those skilled in the art. Furthermore, the control device C can be connected to a sensor 22 designed to determine whether an object to be detected has been placed on the document support 12.

[0029] According to the invention, the following steps can be provided for operating the control device C. First, the sensor 22 determines whether an object to be detected has been placed on the document support 12 (step S10) and sends a corresponding signal to the control device C. In a step S20, for example, in response to the signal transmitted in step S10, the control device C causes the detection sections 14.1, 14.2 of the document support 12 to be illuminated by the lighting arrangement B.

[0030] In a step S30.1, the control device C controls the first capture section 14.1 to make it transparent, and simultaneously or slightly offset in time, triggers the first capture device 18.1 to create an image of the first document section D1 resting on the first capture section 14.1 (step S40.1). Subsequently, in a step S50.1, the first capture section 14.1 is made opaque again.

[0031] Subsequently, in a similar manner, in a step S30.2, the control device C controls the second capture section 14.2 to make it transparent, and simultaneously or slightly offset in time, triggers the second capture device 18.2 to create an image of the second document section D2 resting on the second capture section 14.2 (step S40.2). Subsequently, in a step S50.2, the second capture section 14.2 is made opaque again.

[0032] Finally, there is one image from each of the cameras 18.1 and 18.2, and a processor (which may, for example, be part of the control device) can calculate which of the two images represents a capture of the "correct" passport page in order to forward it, in a manner known per se, for further processing within the framework of the electronic border control (step S60: identifying the document section to be further processed).

[0033] The invention is thus a full-page passport reader that allows the reading of an opened passport without requiring the correct alignment / orientation of the passport pages. The idea of ​​the invention is to duplicate the optical system for scanning a single passport page and to provide a camera and a (deflecting) mirror for scanning each of the two adjacent passport pages. List of reference symbols

[0034] 10Device for optically capturing a document 12Document support 14Surface 14.1First capturing section 14.2Second capturing section 16Optical capturing arrangement 18.1First capturing device 18.2Second capturing device 20.1First deflecting mirror 20.2Second deflecting mirror 22Sensor BBillumination element CControl device DDocument D1first document section D2second document section S10Detecting the applied passport S20Illuminating S30Transparent switching S40Triggering S50Non-transparent switching S60Identifying

Claims

1. Apparatus (10) for optically capturing a document (D), comprising a document support (12) with a surface (14) for placing a document (D) thereon, wherein the document support (12) comprises a first capture section (14.1) and a second capture section (14.2), which are designed such that the first capture section (14.1) is assigned to a first document section (D1) of a document (D) which is placed on the surface (14) and the second capture section (14.2) is assigned to a second document section (D2) of the placed document (D), at least one illumination element (B) for illuminating the surface (14), and an optical capture arrangement (16) for detecting light which is reflected by the placed document (D), wherein the capture arrangement (16) comprises a first capture device (18.1), which is assigned to the first capture section (14.1), and a second capture device (18.2), which is assigned to the second capture section (14.2), wherein the first capture section (14.1) and the second capture section (14.2) are designed to be switchably transparent, and a control device (C) which is designed such that successive transparency switching of the first capture section (14.1) and the second capture section (14.2) takes place is provided.

2. Apparatus (10) according to Claim 1, wherein a first deflection mirror (20.1) for deflecting light from the first capture section (14.1) to the first capture device (18.1) is provided and a second deflection mirror (20.2) for deflecting light from the second capture section (14.2) to the second capture device (18.2) is provided.

3. Apparatus (10) according to Claim 2, wherein the first and / or the second deflection mirrors (20.1, 20.2) are partially transparent.

4. Method for optically capturing a document (D), which has been placed with a first document section (D1) and a second document section (D2) on a document support (12) in a manner such that the first document section (D1) lies on a first capture section (14.1) of the document support (12) and the second document section (D2) lies on a second capture section (14.2) of the document support (12), comprising the steps of: - illuminating (S20) the document sections (D1, D2) of the placed document (D), - triggering (S40.1) a first capture device (18.1), which is assigned to the first capture section (14.1), to capture the first document section (D1), - triggering (S40.2) a second capture device (18.2), which is assigned to the second capture section (14.2), to capture the second document section (D2), wherein the first and the second capture sections (14.1, 14.2) are designed to be switchably transparent, and before or during the step of triggering (S40.1) the first capture device (18.1), which is assigned to the first capture section (14.1), the first capture section (14.1) is switched to transparent (S30.1), and before or during the step of triggering (S40.2) the second capture device (18.2), which is assigned to the second capture section (14.2), the second capture section (14.2) is switched to transparent (S30.2).

5. Method according to Claim 4, comprising the further step (S60) of identifying the document section (D1, D2) to be processed further.

6. Computer program having program code means to carry out all the steps of a method according to any of Claims 4 to 5 when the computer program is executed on a suitable computer device or control device (C).